Train of thought navigation:
Oil and barrel *** 15 kg, half eaten, and oil and barrel * * * weigh 8 kg, that is to say, 15 kg is divided into two parts, one part is half eaten oil, and the other part is the remaining oil and barrel * * * weighing 8 kg. Take 8 kg from 15 kg, and the rest should be half of the oil. 15-8=7 (kg). Half a barrel of oil weighs 7 kilograms, and a full barrel of oil can be found out.
15-8=7 (kg) 7×2= 14 (kg) Answer: I ate 7 kg of oil, and the oil in a full barrel weighed 14 kg.
Crazy sports:
1. A bucket of water weighs 250kg. After using half of it, the barrel weighs 145 kg. How many kilograms of water was used?
How much does a full bucket of water weigh?
2. Weight of a barrel of oil 16kg. Half of the oil is used, and the barrel weighs 9 kilograms. How many kilograms of crude oil? How much does this bucket weigh?
3. Grandma Wang bought dates in a cardboard box weighing 1 kg. After filling a box of dates, weigh 1 1 kg. Now Grandma Wang wants to give half of the dates she bought to Aunt Li. How many Jin does Grandma Wang want to give Aunt Li?
Example 2: Tian Tian has been practicing writing for 8 days. Practice 4 sheets of paper every day for the first 7 days and 5 sheets on the last day. (of lotus leaves floating on the water) elegant.
How many sheets of paper did you practice writing in 8 days?
Train of thought navigation:
Because we practice four sheets of paper every day for seven of the eight days, we can use 4×7=28 (sheets) to find out the total number of practicing writing in the first seven days. On the last day, I practiced 5 sheets of paper, and then used 28+5=33 (sheets), which is the number of sheets I practiced writing in 8 days.
The formula is as follows: 4×7+5.
=28+5
A: I wrote 33 articles in eight days.
Crazy sports:
1. Xiaoming read a story book. He read 12 pages every day for the first five days, and just finished reading 20 pages on the last day. How many pages does this story book have?
Master Zhang produces a batch of parts. In the first four days, he produced 25 parts every day, and in the next three days, he produced 60 parts. How many parts does Master Zhang produce a week?
3. The students planned to bind 300 books in five days. As a result, 160 books were bound in the first three days, and 20 books were left unfinished after the last two days. How many books did the students bind in the next two days?
Example 3: Xiaoming read 7 pages a day for the last book, and there were 35 pages left after 6 days. How many days does it take Xiao Ming to finish reading this book?
Train of Thought Navigation: First, read 7 pages a day for 6 consecutive days, and we can find that we have read 6×7=42 (pages), then read 42 pages, and there are 35 pages left, and we can find that the book * * * has 42+35=77 (pages), so it takes Xiaoming 77 ÷ 7 = to finish reading this book. In addition, the title tells us that we have read it for 6 days, and there are 35 pages left, so how many days will it take to finish it? According to "7 pages a day, there are 35 pages left", we still need to look at 35÷7=5 (days), so we can find that a * * * needs 6+5= 1 1 (days). The formula is as follows:
(6×7+35)÷7 or 35÷7+6
=(42+35)÷7 =5+6
=77÷7 = 1 1 (days)
= 1 1 (days)
A: It takes 1 1 day for Xiao Ming to finish reading this book.
Crazy sports:
1, a pile of coal, 3 tons each time, 42 tons left after 8 times, how many times will this pile of coal be transported?
2. Master Zhang processes a batch of parts, processing 10 pieces every day, and there are 40 pieces left after 8 days. How many days does it take to finish the processing of these parts?
3. Lingling reads books, and plans to read 10 pages every day, 15 days. She actually reads five more pages every day. How many days did Lingling actually spend reading this book?